Motor-starting switch



Dec.

1,477,871 B. E. GETCHELL MOTGR STARTING SWITCH Filed June 27. L922 2Sheets-Sheet 1 Fig; 1

INVENTOR 13, 1923* 12 1 B, E. GETCHELL MOTOR STARTING SWITCH 2Sheets--Sheet 2 Filed June 27 1922 INVENTOR Patented Dec. 18 1923.

UNITED STATES PATENT OFFICE. v

BENJAMIN E. GETCHELL, 0F PLAINVILLE, CONNECTICUT. ASSIGNOR TO THE TRUE-BULL ELECTRIC MANUFACTURING COMPANY, OF ILAI'NVILLE, CONNECTICUT, A

CORPORATION OF CONNECTICUT.

MOTOR-STARTING SWITCH.

T 0 all whom it may concern:

Be it known that I, BENJAMIN E. Gnrcm ELL, a citizen of the UnitedStates of America, residing at Plainville, Connecticut, have invented anew and useful Motor-Starting Switch of which the following is sspecification.

This invention relates to switches which may be opened and closed byhand, but is more particularly directed to switches for controllingmotor circuits, and which release automatically upon undue variations inthe load, thereby protecting the motors.

An important object of the invention is to provide a. simple, ruggedswitch mechanismv arranged to be closed by hand, and to be opened eitherby hand or automatically in response to certain changes in the load orline voltage.

A further object is to provide such a. switch having powerful meansconstantly urging the inovuble contacts to open circuit position whilebut a small amount of energy is required to hold the contacts in closedposition when the load is normal.

A further object of the invention is to wear to give a quick break ofthe switchcontacts.

Other objects of the invention will be come n iipurent as thedescription progresses.

ln carrying out the invention there are provided :1 contact operatingmember. means such as a spring to actuate said member to open theswitch. a. toggle joint or member having one part connected to theoperating nicnrbcr. and an elcctrmnugnet connected'in the load circuithaving an armature connected to the other part oi the toggle to hold thetwo parts in locking alignment to main tain the switch closed when themagnet is normally energized.

One embodiment of the invention is i1lnstinted in the accompanyingdrawings in which:

Fig. 1 is a perspective view with certain parts broken away of a switchand its operating means.

Fig. 2 is a central longitudinal section of the switch with the contactsclosed, and

Fig. 3 is a similar section talnen on :2. slightly different planeshowing the contacts open.

. A casing 4 of any desired type houses the entire switch which issupported on an insu lating base secured the casing as by the screws 5.The circuit closing members may comprise any desired number of blades ormovable contacts 7, each pivoted on a post 8 for engagement with astationary contact such as spring clip 9, three sets of contacts beingshown in the drawings. An insulating cross-bar 10 is connected 'as byangle pieces 11 to the blades 7. An operating handle 12 is journalled atone end 13 in one side of the casing 4. A crank shaped contactoperating-member 14 has one end secured for rotation with the. end 13 ofthe handle, while its other end is journalled in the opposite wall ofthe casing. Operating member 146 may be connected to her 10 by anysuitable linkage. but when an automatic quick break of the switchcontacts is desired, crank l -l passes through a number of links 15carried by bar 10. lVhen this construction is eIn-- ployed, a tensionspring 16 provided near each link to connect the her and crank. A spring17 stretched bet ween operating crank 14 and a tired point such as thebottom well of easing 4i constantly urges the crank and thus the movablecontacts 7 into open circuit position, and normally holds the crankngninst it stop 18 secured to the left hand WIll of the casing, with theswitch parts in 'the position shown in F ig. 3.

- To hold the switch in closed position while the load current isnormal, a magnet and toggle joint are provided. The magnet com prisesangle plates 19 secured to base 5 in spaced relation as by screws 20.Riveted between plates 19 is it U-shnped core 2i for instance oflaminated iron. about the upper leg of which is coiled the winding 22 ofthe magnet. Plates 19 extend downwardly and ted iron sheets 26 arrangedto fit. snugly ageinst the ends of core 2]. when the armature isattrected. f t-copper separator 27 may be cincriedat the upper end ofthe armature to prevent its sticking to the core when l nersg'iaed, inwhich case the lower leg of the core is longer hy the thickness of theaerator 27 than the upper leg, as best seen 4 3. lln any case the slots25 permit in suttlcient play of pin 24 to allow the armature to adaptitself to the core. and secure an strong magnetic attraction with asmall current ll lO W in the winding 22. Frame have cars 28 which bear.against 21 to limit opening movement of the The armature acts as onepart of a toggle joint, the other part consisting of a longitudinailyslotted bar 29 journalled at its upper end near the mid-point of crank'14: while tslower portion slides between margins 30 ct plates 23 whichare inwardly bent to hide it seen in 1. A roller 31 is mounted on a pin32 carried between the lower ends of margins 30 ot armature plates Thisroller carries the thrust exerted on bar 29 by the spring 17 so long asthe switch is cosed and bar 29 is in locking alignment with thearmature. pin 33 passes through the slot in bar 29 and 'illliTOllfId theupper ends of armature plates tel to hold the bar in alignment with thearmature when the latter is attracted. and serves to retract thearmature when the magdeenergizes and the lower end of bu r 25? slit esfree of roller 31. Since spring 11' eaerts no lilting" force on bar 29,tl1e lower of the bar is preferably given a slight evel, best seen inFig. 3, so tha't the aownward pressure of the bar on roller 32 (is tolift the bar free of the ro'ler and met the armature. Such bevel ishower not essential to operation of the toggle oint, since the thrust ofbar 29 produces 1, couple which acts on pins 32. and 2st tendup; toretract the armature, and thus to lift ar 29 by means of pin 83 and thepressure the upper-ends o'lf sheets 26 on the bar. in n switch of thetype described which adapted to he used for example with a e phase powerline or a three wire two so line, the line wires are connected to clips9 b7 the usual terminals Motor termi als 34 are secured to '19 5 nearthe bottom of the casing, the two-outer terminals having sprinfi clips35 till iilireet to its post 8 as by the insuial while the middleterminal 34: is

inn? shown. @uter posts 8 have spring ps lit in alignment with clips 35,while between each of these pairs are clips 3? indepen ently secured tothe insulatine; base Hagnet winding connected between clips 37. A relay36, it? norma-Ily serves to interconnect the clips, but is arranged uponthe continuance of an over oad condition for u predetermincd timeinterval (which is short enough to prevent damuge to the motor) todisconnect clips 37 from the line circuits.

llhus upon closure of the switch by operation of the handle 12, thecontact oi the switch '2' with jaw post 9 completes the circult throughwinding 22 in shunt with the motor to energize the magnet and thus drewthe bar 2:9 am} armature 23 into alignment and lock the toggle jointmembers against the action of spring l7. and the switch remains closed.Should an underuoltagre condition arise, the current in winding 22 wouldbecome too weak to hold the armature attracted, and spring 17 would openthe switch. Similarly if an overload condition arises, relays 38 willinterrupt the circuit of windin 22 before the motor has become 38 heldby each set of clips 31., V

overheate and the switch will be opened.

Whether the switch is opened by hand ,or by the spring 17 upondeenergiaation ot the magnet, the operating crank 14- moves as far asthe outer end of limits 15 without dis turbine: the blades 7 (as shownin broken lines in Fig. 2) and thus puts springs UH- der considerabletension. When upon fun th er movement of the cranlr the blades arewithdrawn from clips 9., the springs 16 suddenly contract to cause avery quick break between the contacts by snapping cross bar 1.0 towardsthe crank until the latter abuts the inner end of the links in theposition shown in Fig. 3. The blades at the instant of opening thereforehave a velocity towards the cranlr'caused by springs 16, while the crankhas velocity towards its stop 18 caused by spring; 17, a resu'ltot whichthe blades leave their spring c ips 9 at a speed equal to the sum of thetwo velocities mentioned, and thereby minimize arcing and consequentwear. i i

To still further decrease arcing 'hetween the contacts, and topositively prevent any are'to' the walls oi the casing, there may beprovided are snuliers 39 of insulating" com position. Each snuiler i-ltlcomprises" two plates 40 united by across strip all. and pivoted to aclip 9 as at 42. The Sl'lllllGI'S are actuated by rods 43 pivoted toblades 7 at 44 and to the out side of plates l-O as at it will thus beapparent that when the switch isclosed', snufi'ing piece ll will haveone'edgc close to blade 7, and as the blade moves out ltlll lltl ias

of engage ment with its clip 9, piece 41' will y be interposed betweenblade and clip to ll' the arc, while plates 40 at all times preventarcing between clips 9 and the casing 4.

While one embodiment of the invention as applied to a particular motorstarting switch has been described in detail, it is to be un' derstoodthat the invention is capable of man other embodiments as may berequired in ifierent applications, and that certain parts may be changedor dispensed with entirely without departing from the spirit of theinvention as defined by the appended claims.

I claim:

1. In a switch, a fixed contact, a movable contact, a crank to actuatethe movable contact, a magnet comprising an armature havihg a stop, abar journalled on the crank and having an end portion abutting themature stop when the contacts are closed,

and means for forcingsaid end portion out of abutment with the stop topermit opening of the contacts.

2 In a switch, a fixed contact, a movable contact, means including a barto control the movable contact, two guide plates for the bar, a stopbetween the guide plates, a pin and slot connection between the bar andguide plates, a support on which the guide plates are pivoted, a springf rcing the bar against the stop when t e contacts are closed, anarmature carried by the guide plates, the pressure of the bar on thestop tending to retract the armature to permit the bar to slide oil thestopto open the contacts, a magnet to attract the armature to preventsuch sliding of the bar.

3, In a switch, two relatively movable contacts, a member to operate thecontacts, a spring to open the contacts, a magnet having an armature, astop carried by the armature and a bar slidably connected to thearmature and secured to the contact operating member, said bar beingarranged upon closing of the contacts to be moved into alignment withthe stop to prevent opening of the, contacts and said pin and Slotconnection maintaining said alignment while the magnet is energized.

4. In a switch, a fixed and a movable contact, an operating member forthe movable contact, a relatively weak spring interconnecting saidmember and contact, and a relatively s1 roug spring opposing the actionof the weak spring and urging the operating member to open the contactssaid strong spring being adapted to initiate opening movement of theoperating member to stretch the weak spring before the contacts openwhereby the movable contact is disengaged from the fixed contact by thesimultaneous contraction of both springs, a bar connected to theoperating member, an in mature arranged when attracted to hold the barin position to prevent contact opening movement of the operating member,and an clectromagnet to attract the armature.

5. In a switch a fixed and a movable contact, an opera! ng member "forthe movable contact, a spring to ac uate the operating member to openthe contacts, a longitudinally slotted bar journalled on the operatingmember, two guide plates conncctcd by a pin passing through the barslot, an armature carried by said plates, a roller stop between saidplates adapted to be engaged by said bar to prevent contact openingmovement of said contacts when said armature is attracted, and a ma netto attract said armature.

6. in an electric switch, a contact blade, an operating crank. having alost motion connection therewith, a spring connecting said crank withsaid blade, another spring more powerful than the first teiyding to0perate said crank, a jointed memacr connected to said crvnk adapted tooppose the action of said operating spring: and hold said crank andswitch blade in the closed circuit position, under certaincircumstances, and an electromagnet for holding one part of saidhingedmcmber, the other part of said hinged member having aslidingengagement with the first mentioned )art when the electro-magnetis dcenergized 7 In a switch, a movable contact, an operating memberconnected thereto, an electro-magnet, a pivoted armature therefor, anabutment carried by said armature, a bar connected to said operatingmember and having a hinged and sliding engagement with said armature andadapted to engage said abutment, and an operating spring holding saidoperating member under tension, said bar and armature holding the switchcontact, in the closed circuitoosition when said magnet is energized,sai spring serving to disengage said bar from said abutment whenthemagnet is deenergized.

8. In an electric switch, an operating member, an electro-magnct, apivoted armature for said magnet, an abutment carried by said armature,a bar connected to said opcirating member. and having a slidingengagement with said armature and adapted o engage silhd abutment whenin a closed circuit position, the moment arm of said abutment beingmaterially shorter than the moment arm of said armature with respect tosaid magnet.

9. In a switch, fixed contacts, movable contacts, an operating member toactuate the movable contacts, a magnet including an armature having astop, a bar connected with the operating member and having an abrupt endadapted to abut against the ar- AW! on] inoture stop when the switch isin closed position end spring for constantly urging" the switch to openposition, the said magnet being Mapted to retain the armature stop inabutment with the abrupt end of said her when the switch is in closedposition.

vl0. lln a switch, fixed contacts, movable contacts, on operuting memberto actuate the movable contacts, 2i magnet including an armature havingstop, a hair connected to the opers ting member and having a sub--stentielly square end portion adapted to abut ogeinst the armature stopwhen the switch is in closed position Blind e spring for constantlyurging the switch to open osition, the said magnet losing adapted to101d the armature stop and the square end of the said her in abuttingrelation against the power of the spring when the switch is in closedposition. v

11. in u switch, fixed contacts, inovohle contacts, :1 crank member tosctuote the movable contacts, a magnet, e pivoted erumture for seidmagnet having a stop, 2, bar connected to said crank member and having asliding engagement with said armature, said having an abrupt end portionadopted to abut against the armature stop when the switch is in closedposition end a spring for constently urging the switch to open position,the said magnet constituting zi'ineens for retaining the abrupt end ofsaid -l)fti in abutment with the said stop against the power of thespring when the switch is in closed position. i

12. in a switch, lined contacts, movable 'contocts, an operatingzneiiiher to actuate the movable contacts, ainagnet including anarmature having a stop, a bar journelled on the operating member andhovin opernhle engagement with the armature, the said her having one ofits ends adapted for on gzurement with the armature etc when the switchis in closed position on a. spring meens tor constantly urging theswitch .to open position, the said magnet beingadeptcd to hold the saidher in abutment with the said step egiiinst the power of ,the springwhcnthe switch is closed.

13, lfn a switch, fixed contacts, movable contacts, on operating cranktor actuating ,the movable contacts. it inugznet including an erinuturchovii it stop, it her journzilled on the operating crurk and having oneof its ends adapted to shut against the armature stop when the switch isin closed position, :1 spring constantly urging the crank to open theswitch, the said magnet beingndupted to retain the he: and armature stopin abutment against the tension of the spring when the switchiis closedsti l the angular relation of said her with said armature. stop beingsuch that the shutting engagement will be broken and the switch Willloethrown open by the spring upon s. reduction. in vol"- position and aspring for throwing the ,ably connecting said armature frame and.contacts, a movable member, it stop ego and the abutting engagement menbroken and the switch opened by the inn. ual operation of the crunlt.

1 in o. switch, fixed contents, contacts, on operating Cflfili for o.the movable contscts, s. magnet in h armature having rotatable siloersbly connecting the said c'rani. i' said armature, said linlt having;one ends adapted for abutment against mature stop when the switch inclosed] 1 o c-vshlc switch to open position, the said inegneconstituting, a means for holding the clout 3 went end of said link inengagement with said rotatable stop against the switch-ope 1- ing forceof the spring when the switch s in closed position.

if). in a switch including pertinent lined and movable contacts, onoperating crank 33 for actuating themovirhle contacts, 11 meg notincluding on ai'n'isture end a pivoted urmoture -trance supporting saidarmature and e rotatable stop, a link 'inemher ope so said operatingcrank and having one of its ends adapted to be drawn into locking ubutment with the said stop by the magnet hen the switch is in closedposition means constantly urging the switch to open posi- 95 tion anduuuuml means For disruptingthe 4 locking engagement of the link and stopto open the switch.

1". ln nswitch including; pertinent l and movable contacts, a crank foroperepin the movable contacts, a movable P supporting a stop, a linkopcmhl coon ing said crank and said member 2 one of its ends adapted toshut ago said stop when the switch is in c sition, magnetic means forholdi, link and said step in locking alumna the circuit is on, 1' springfor d said locking engagement of the stop when the circuit is de-cner"for constantly urging the switch to on position and nmnuul means {odisrupt the locking engagement of said lint: 2 stop to open the switch.

17. In a switch, lined contacts. movable contacts, a crank for actuatingthe movable sun ported by said member, o linlc opeifliol cohnecting saidcrank with said member and having one oi its ends adapted to shutagainst the said stop when the switch is in closed position with thenormal circuit on, mhgnctic means for holding Sit-id link and stop inabutting solution when the nor-incl circuit is on and for releasing saidabut-ting relation when the circuit is tlc-energizech spring" means forconstantly urging the switch to oft" position and manual inserts fordisrupting the abutting reletion oii the linlr and stop to open theswitch,

ice

1 engagement with semi armature and Um! tgyengage said stop, a springacting said .iink and a magnet acting upon Mair? armature to mid 119parts in closed *3 "nosiuion. a S'WiiCl, a magnet, an armature pimied3'6 end to swing toward away from the magnet, :2, stop carried by midarmature adjacent its pivot, a link 1121* ing a sliding enga ezneniiwith the apposite and 91: said armature and adapted to abut against saidstop in the closed circuit positiufi and means for actuating said link.

BENJAMIN E "GETCHELL.

